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      <title>SpringCloudAlibaba - 交互式测验</title>
      <style>
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        .option-item:hover {
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        .option-item.selected {
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        .quiz-footer {
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          display: flex;
          justify-content: space-between; /* 将按钮分布在两侧 */
          align-items: center;
          min-height: 65px; /* Reserve space */
        }

        .nav-btn {
          background-color: #4a90e2;
          color: white;
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          border-radius: 8px;
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          cursor: pointer;
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        .nav-btn:hover {
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        #result-container {
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        .result-box {
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        .result-box h3 {
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        .source-text {
            font-style: italic;
            font-size: 14px;
            margin-top: 15px;
            color: #555;
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        .final-score-container h2 {
            margin-top: 0;
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            display: flex;
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            gap: 20px;
            margin-bottom: 40px;
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            background-color: #f8f9fa;
            border-radius: 12px;
            padding: 20px;
            width: 180px;
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            font-size: 16px;
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            font-size: 15px;
            line-height: 1.6;
            display: none; /* 默认隐藏 */
        }
      </style>
    </head>
    <body>
      <div class="main-wrapper">
          <div class="quiz-container">
            <div class="quiz-header">
              <h1>SpringCloudAlibaba - 交互式测验</h1>
              <p>检验你对文档内容的理解程度</p>
            </div>
            <div id="quiz-content">
                <div class="quiz-body">
                    <div class="progress-bar">
                        <div id="progress-indicator"></div>
                    </div>
                    <div id="question-container">
                      <p id="question-text"></p>
                      <ul class="options-list" id="options-list"></ul>
                    </div>
                    <div id="result-container"></div>
                    <div id="hint-container" class="hint-container"></div>
                </div>
                <div class="quiz-footer" id="quiz-footer">
                  <button id="prev-btn" class="nav-btn">上一题</button>
                  <button id="hint-btn" class="nav-btn" style="background-color: #ffc107; color: #333; box-shadow: 0 4px 12px rgba(255,193,7,0.3);">提示</button>
                  <button id="next-btn" class="nav-btn">下一题</button>
                </div>
            </div>
          </div>
      </div>

      <script>
        const quizData = [
  {
    "question": "在使用Nacos作为配置中心时，Spring Cloud应用默认会根据什么规则来构建配置文件的Data ID？",
    "options": [
      "${spring.application.name}.${file-extension}",
      "${spring.application.name}-${spring.profiles.active}.${file-extension}",
      "${spring.profiles.active}-${spring.application.name}.${file-extension}",
      "${group}/${spring.application.name}.${file-extension}"
    ],
    "correctAnswerIndex": 1,
    "explanation": "Nacos配置中心的Data ID默认拼接规则为 \"服务名-环境名.文件后缀\"，即 `${spring.application.name}-${spring.profiles.active}.${file-extension}`。当 `spring.profiles.active` 为空时，连接符 `-` 也会被省略，变为 \"服务名.文件后缀\"。",
    "source": "文档中「6、Nacos配置中心」->「从Nacos中拉取配置文件」部分",
    "hint": "文档中提到，Data ID的拼接格式与 `spring.application.name` 和 `spring.profile.active` 都有关。"
  },
  {
    "question": "为了使Spring Boot应用能够动态感知并刷新Nacos配置中心的变化，除了在Nacos控制台修改配置外，还需要在客户端代码的相应组件上添加哪个关键注解？",
    "options": [
      "@EnableDiscoveryClient",
      "@RefreshScope",
      "@ConfigurationProperties",
      "@DynamicConfig"
    ],
    "correctAnswerIndex": 1,
    "explanation": "@RefreshScope注解能够使相关的Bean在一个特殊的\"refresh\"作用域中。当配置发生变化时（例如通过/actuator/refresh端点触发），这些Bean会被销毁并基于新配置重新创建，从而获取到最新的配置值。",
    "source": "文档中「6、Nacos配置中心」->「Nacos配置动态刷新」部分",
    "hint": "文档中有一个Controller类的代码示例，在其类声明上添加了一个注解以实现配置的实时刷新。"
  },
  {
    "question": "为什么在生产环境中搭建Nacos集群时，官方强烈建议将数据持久化到外部MySQL数据库，而不是使用默认的嵌入式数据库？",
    "options": [
      "因为嵌入式数据库Derby性能较差，无法满足生产环境的高并发需求。",
      "因为MySQL提供了更强大的数据加密功能，安全性更高。",
      "因为默认的嵌入式数据库不支持集群模式，每个节点数据独立，无法保证数据一致性。",
      "因为嵌入式数据库会占用过多的JVM内存，导致Nacos服务不稳定。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "Nacos默认使用嵌入式数据库Derby，这在单机模式下工作良好。但在集群模式下，每个Nacos节点都有自己的Derby数据库，导致数据无法同步和共享。为了解决这个问题，Nacos支持使用集中式的MySQL数据库来存储数据，从而确保所有集群节点的数据一致性。",
    "source": "文档中「7、Nacos持久化」部分",
    "hint": "文档提到：“如果启动多个默认配置下的Nacos节点，数据存储存在一致性的问题。”"
  },
  {
    "question": "在Spring Cloud Gateway中，`Predicate`（断言）的核心作用是什么？",
    "options": [
      "在请求转发前后修改请求头或响应体。",
      "定义一组路由转发的判断条件，只有满足条件的请求才会被该路由处理。",
      "指定请求的目标URI，即最终要转发到的微服务地址。",
      "实现对下游服务的负载均衡策略，如轮询或随机。"
    ],
    "correctAnswerIndex": 1,
    "explanation": "`Predicate`是路由的基本组成部分之一，它是一组用于匹配请求的条件。例如，可以根据请求的路径（Path）、请求头（Header）、时间（After/Before）等多种条件进行判断。只有当请求满足了路由中定义的所有`Predicate`时，该请求才会被转发到指定的URI。",
    "source": "文档中「8、服务网关-Gateway」->「Gateway核心组件」部分",
    "hint": "文档中对Gateway核心组件的定义是：“路由转发的判断条件”。"
  },
  {
    "question": "Nacos支持临时实例和持久化实例两种模式，它们在服务下线时的行为有何根本区别？",
    "options": [
      "临时实例下线后会立即从服务列表删除，而持久化实例下线后会保留在列表中，仅状态标记为不健康。",
      "临时实例必须由客户端主动注销，而持久化实例可以由服务端自动摘除。",
      "临时实例的信息存储在内存中，持久化实例的信息存储在MySQL数据库中。",
      "临时实例使用AP架构（保证可用性），持久化实例使用CP架构（保证一致性）。"
    ],
    "correctAnswerIndex": 0,
    "explanation": "临时实例通过客户端心跳保活，当Nacos在规定时间内未收到心跳时，会将其标记为不健康，并最终从服务列表中删除。而持久化实例由服务端主动进行健康检查，即使实例下线，Nacos也仅会将其健康状态置为不健康，但不会从列表中删除，便于运维人员监控和介入。",
    "source": "文档中「10、Nacos集群」->「Nacos集群原理」部分",
    "hint": "思考一下两种模式对于“实例不存在”这一情况的不同处理方式。"
  },
  {
    "question": "在Spring Cloud中，客户端负载均衡组件Ribbon默认采用的负载均衡策略是什么？",
    "options": [
      "RandomRule (随机策略)",
      "BestAvailableRule (最低并发策略)",
      "ResponseTimeWeightedRule (响应时间加权策略)",
      "RoundRobinRule (轮询策略)"
    ],
    "correctAnswerIndex": 3,
    "explanation": "Ribbon提供了多种负载均衡策略。如果没有进行任何自定义配置，它默认会使用`RoundRobinRule`，即轮询策略，按顺序依次将请求分发给服务实例列表中的每个可用实例。",
    "source": "文档中「5、Nacos服务发现」->「Ribbon负载均衡策略」部分",
    "hint": "文档中有一张列表清晰地列出了多种策略，并明确指出了Ribbon的默认策略。"
  },
  {
    "question": "在Spring Cloud Gateway的路由配置中，`filters: - StripPrefix=1` 的作用是什么？",
    "options": [
      "为请求路径添加一个前缀，例如将 `/hello` 变为 `/api/hello`。",
      "在转发请求前，从请求路径中移除第一个路径段。",
      "要求请求路径必须包含指定的前缀才能匹配该路由。",
      "移除请求头中名为 \"Prefix\" 的第一个值。"
    ],
    "correctAnswerIndex": 1,
    "explanation": "`StripPrefix` 是一个内置的过滤器工厂，用于在将请求转发到下游服务之前修改请求的URI。`StripPrefix=1` 表示剥离（移除）路径中的第一个部分。例如，如果网关收到的请求是 `/provider/hello`，经过此过滤器处理后，转发给后端服务的路径将是 `/hello`。",
    "source": "文档中「8、服务网关-Gateway」->「GatewayFilter Factories」->「StripPrefix」部分",
    "hint": "思考一下 \"Strip\" 这个词的含义，以及它如何应用于URL路径。"
  },
  {
    "question": "在Nacos中，`Namespace`（命名空间）的主要用途是什么？",
    "options": [
      "对不同业务模块的配置进行逻辑隔离，例如订单模块和用户模块。",
      "将同一微服务的不同版本配置进行分组管理。",
      "用于进行租户级别的资源隔离，最常见的场景是区分不同的部署环境，如开发、测试和生产环境。",
      "定义一组配置的数据格式，如 `properties` 或 `yaml`。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "`Namespace` 提供了最高级别的隔离。它的设计初衷是用于多租户场景，但在实际应用中，最常见的用途是隔离不同的部署环境（如开发环境、测试环境、生产环境）。不同的`Namespace`下的配置和服务是完全隔离的，可以存在相同的Group和Data ID。",
    "source": "文档中「6、Nacos配置中心」->「Nacos配置中心其他参数」->「Namespace」部分",
    "hint": "文档中提到：“Namespace的常用场景之一是不同环境的配置的区分隔离”。"
  }
];
        console.log("Quiz Data:", JSON.parse(JSON.stringify(quizData))); // 添加这行用于调试，以可展开的JSON格式输出
        
        let currentQuestionIndex = 0;
        let score = 0;
        // 存储每个问题的回答状态
        const userAnswers = new Array(quizData.length).fill(null); 

        const questionTextEl = document.getElementById('question-text');
        const optionsListEl = document.getElementById('options-list');
        const resultContainerEl = document.getElementById('result-container');
        const quizContentEl = document.getElementById('quiz-content');
        const progressIndicatorEl = document.getElementById('progress-indicator');
        const prevBtn = document.getElementById('prev-btn');
        const nextBtn = document.getElementById('next-btn');
        const hintBtn = document.getElementById('hint-btn');
        const hintContainerEl = document.getElementById('hint-container');

        function loadQuestion() {
          resultContainerEl.innerHTML = '';
          optionsListEl.innerHTML = '';
          hintContainerEl.style.display = 'none'; // 隐藏提示
          
          if (currentQuestionIndex >= quizData.length) {
            showFinalScore();
            return;
          }

          updateProgress();

          const currentQuestion = quizData[currentQuestionIndex];
          questionTextEl.textContent = `(${currentQuestionIndex + 1}/${quizData.length}) ${currentQuestion.question}`;
          
          currentQuestion.options.forEach((optionText, index) => {
            const li = document.createElement('li');
            li.className = 'option-item';
            li.textContent = optionText;
            li.dataset.index = index; // Store index in a data attribute
            // 如果这道题已经回答过，恢复状态
            if (userAnswers[currentQuestionIndex] !== null) {
                if (index === userAnswers[currentQuestionIndex]) {
                    li.classList.add('selected');
                }
            }
            optionsListEl.appendChild(li);
          });

          // 如果已经回答过，直接显示结果
          if (userAnswers[currentQuestionIndex] !== null) {
              const isCorrect = userAnswers[currentQuestionIndex] === currentQuestion.correctAnswerIndex;
              showResult(isCorrect, currentQuestion);
          }
          
          updateNavigationButtons();
          updateProgress();
        }

        function selectOption(optionIndex) {
            userAnswers[currentQuestionIndex] = optionIndex;
            const currentQuestion = quizData[currentQuestionIndex];
            const isCorrect = optionIndex === currentQuestion.correctAnswerIndex;

            // 重新计算分数
            score = userAnswers.reduce((acc, answer, index) => {
                return answer === quizData[index].correctAnswerIndex ? acc + 1 : acc;
            }, 0);

            showResult(isCorrect, currentQuestion);
            updateNavigationButtons();
        }
        
        function updateProgress() {
            const answeredQuestions = userAnswers.filter(answer => answer !== null).length;
            const progressPercentage = (answeredQuestions / quizData.length) * 100;
            progressIndicatorEl.style.width = `${progressPercentage}%`;
        }
        
        function updateNavigationButtons() {
            prevBtn.style.display = 'block';
            nextBtn.style.display = 'block';
            hintBtn.style.display = 'block'; // 显示提示按钮

            prevBtn.disabled = currentQuestionIndex === 0;
            nextBtn.disabled = false; // 最后一题时，下一题按钮不禁用，而是用于显示报告
            nextBtn.textContent = (currentQuestionIndex === quizData.length - 1) ? '查看报告' : '下一题';
            
            // 如果当前问题没有提示，则禁用提示按钮并隐藏提示内容
            if (!quizData[currentQuestionIndex].hint) {
                hintBtn.disabled = true;
                hintContainerEl.style.display = 'none';
                hintContainerEl.textContent = ''; // 清除旧的提示内容
            } else {
                hintBtn.disabled = false;
            }
        }

        function showResult(isCorrect, questionData) {
            resultContainerEl.innerHTML = ''; // 清空之前的结果
            const resultBox = document.createElement('div');
            resultBox.className = `result-box ${isCorrect ? 'correct' : 'incorrect'}`;
            
            let html = `<h3>${isCorrect ? '回答正确！' : '回答错误'}</h3>`;
            if (!isCorrect) {
                html += `<p><strong>正确答案是：</strong> ${questionData.options[questionData.correctAnswerIndex]}</p>`;
            }
            html += `<div class="explanation-text">${questionData.explanation}</div>`;
            html += `<div class="source-text">来源: ${questionData.source}</div>`;
            
            resultBox.innerHTML = html;
            resultContainerEl.appendChild(resultBox);

            // 禁用所有选项的点击事件，并高亮正确/错误答案
            Array.from(optionsListEl.children).forEach((child, index) => {
                child.style.pointerEvents = 'none';
                // 高亮正确答案
                if (index === questionData.correctAnswerIndex) {
                    child.classList.add('correct'); // 需要添加CSS样式
                    child.style.backgroundColor = '#d4edda';
                    child.style.borderColor = '#c3e6cb';
                }
                // 如果选错了，高亮错误选项
                if (!isCorrect && index === userAnswers[currentQuestionIndex]) {
                    child.classList.add('incorrect'); // 需要添加CSS样式
                    child.style.backgroundColor = '#f8d7da';
                    child.style.borderColor = '#f5c6cb';
                }
            });
        }

        function goToNextQuestion() {
            if (currentQuestionIndex < quizData.length - 1) {
                currentQuestionIndex++;
                loadQuestion();
            } else {
                showFinalScore();
            }
        }

        function goToPreviousQuestion() {
            if (currentQuestionIndex > 0) {
                currentQuestionIndex--;
                loadQuestion();
            }
        }
        
        function showHint() {
            const currentQuestion = quizData[currentQuestionIndex];
            if (currentQuestion.hint) {
                hintContainerEl.textContent = currentQuestion.hint;
                hintContainerEl.style.display = 'block';
            } else {
                hintContainerEl.style.display = 'none';
            }
        }

        function showFinalScore() {
            document.querySelector('.quiz-body').style.display = 'none';
            document.getElementById('quiz-footer').style.display = 'none';

            const correctCount = score;
            const totalQuestions = quizData.length;
            const answeredCount = userAnswers.filter(a => a !== null).length;
            const wrongCount = answeredCount - correctCount;
            const skippedCount = totalQuestions - answeredCount;
            const accuracy = totalQuestions > 0 ? Math.round((correctCount / totalQuestions) * 100) : 0;
            const errorRate = totalQuestions > 0 ? Math.round((wrongCount / totalQuestions) * 100) : 0;

            const finalScoreHtml =
                '<div class="final-score-container">' +
                '<h2>答题报告</h2>' +
                '<div class="score-summary">' +
                '<div class="score-card">' +
                '<h3>得分</h3>' +
                '<p>' + correctCount + ' / ' + totalQuestions + '</p>' +
                '</div>' +
                '<div class="score-card">' +
                '<h3>正确率</h3>' +
                '<p>' + accuracy + '%</p>' +
                '</div>' +
                '<div class="score-card">' +
                '<h3>错误率</h3>' +
                '<p>' + errorRate + '%</p>' +
                '</div>' +
                '<div class="score-card score-details">' +
                '<table>' +
                '<tr><td>正确</td><td>' + correctCount + '</td></tr>' +
                '<tr><td>错误</td><td>' + wrongCount + '</td></tr>' +
                '<tr><td>未答</td><td>' + skippedCount + '</td></tr>' +
                '</table>' +
                '</div>' +
                '</div>' +
                '<div class="report-actions">' +
                '<button id="review-btn">回顾测验</button>' +
                '<button class="primary" onclick="location.reload()">再试一次</button>' +
                '</div>' +
                '</div>';

            let reportEl = document.querySelector('.final-score-container');
            if (reportEl) {
                reportEl.remove();
            }
            quizContentEl.insertAdjacentHTML('beforeend', finalScoreHtml);
            document.getElementById('review-btn').addEventListener('click', reviewQuiz);
        }

        function reviewQuiz() {
            const reportEl = document.querySelector('.final-score-container');
            if (reportEl) {
                reportEl.remove();
            }

            document.querySelector('.quiz-body').style.display = 'block';
            document.getElementById('quiz-footer').style.display = 'flex';
            
            currentQuestionIndex = 0;
            loadQuestion();
            updateNavigationButtons(); // Ensure nav buttons are correctly displayed
        }

        // Event Delegation for options
        optionsListEl.addEventListener('click', (event) => {
            if (event.target && event.target.matches('li.option-item')) {
                // Check if the question has already been answered
                if (userAnswers[currentQuestionIndex] === null) {
                    const selectedIndex = parseInt(event.target.dataset.index, 10);
                    selectOption(selectedIndex);
                }
            }
        });

        prevBtn.addEventListener('click', goToPreviousQuestion);
        nextBtn.addEventListener('click', goToNextQuestion);
        hintBtn.addEventListener('click', showHint);
        
        // 初始加载
        loadQuestion();
      </script>
    </body>
    </html>
  